Copy export overview

The copy export function allows a copy of selected virtual volumes that are written to the TS7700 to be removed and taken offsite for disaster recovery purposes.

The copy export function builds on the existing capability to create a copy of virtual volumes on a secondary physical volume pool. When a copy export is completed, physical volumes from the secondary physical volume pool are removed from the library that is associated with the TS7700 and sent to an offsite location for disaster recovery. The benefits of volume stacking, which places many virtual volumes on a physical volume, are retained. Additionally, since the exported data is a copy of the virtual volumes, it remains accessible to the production host system.

Note: The copy export function does not apply to disk-only TS7700 configurations.

Similar to the traditional use of tape for disaster recovery, it is expected that the copy export operation is completed regularly and that additional physical volumes are sent offsite daily. Should the production site become unusable and it becomes necessary to use the offsite volumes for disaster recovery, access to the exported data is reestablished through a disaster recovery procedure instead of a data import procedure:

All exported physical volumes are placed into a library attached to an empty TS7700.
A disaster recovery procedure is invoked through the TS7700 Management Interface.
Note: You must also restore the host environment (tape catalog, tape management system, and so on.).
The disaster recovery procedure reestablishes access to the virtual volumes contained on the exported physical volume.

Although the exported physical volumes are removed from the TS7700 and located outside of the physical library, they continue to be managed by the source TS7700 regarding space management. As virtual volumes resident on the exported physical volumes are expired, rewritten, or otherwise invalidated, the amount of valid data on an exported physical volume decreases until the physical volume becomes eligible for reclamation based on your criteria. When an exported physical volume is reclaimed, it is not brought back to the source TS7700 for processing; instead, a new secondary copy of the remaining valid virtual volumes is made by using the primary virtual volume copy as a source. The next time the copy export operation is performed, the physical volume with the new copies is also exported. The exported physical volumes that were reclaimed and are offsite no longer have valid data and can be returned to the source TS7700 to be used as new scratch volumes.

Note: If two or more TS7700s are configured in a Grid, only one TS7700 can perform a copy export operation at any time.

The Export List Volume is a virtual volume that provides completion status and export operation information for the copy export function. The host that initiates copy export creates an Export List Volume on the TS7700 that performs the operation. The TS7700 performing the operation uses the Export List Volume for project status, export information, and execution instructions. The TS7700 then creates response records in the Export List Volume that list the virtual volumes exported and the physical volume that they reside on. You can use this information as a record for data that is offsite. Finally, the TS7700 writes records in the Export List Volume for any offsite physical volumes that have been reclaimed and no longer contain any active data. The Bulk Volume Information Retrieval (BVIR) function can provide a list of the offsite physical volumes that are empty in the Export List Volume and can be used to obtain a current list of exported physical volumes for a secondary pool. Information is provided for the amount of active data contained by each exported physical volume.

Host Console Request and Host Copy Enable. The Host Console Request (HCR) and Host Copy Enable functions expand the range of copy operations.

The copy export function is also supported by the HCR function. Through HCR, you can request that a physical volume exported with copy export be queued for reclamation, regardless of whether it has met any of the reclaim criteria you have established for the TS7700. You can use the HCR function from the zOS host console to remove a physical volume that is exported with copy export that no longer has any valid data on it. For detailed information about the copy export function, please refer to the IBM® White Paper, IBM Virtualization Engine TS7700 Series Copy Export User's Guide, WP101092, available at the IBM Support & Downloads web page linked in the Related information section.

Host Copy Enable permits the host to enable or disable copies to and from the specified distributed library. A request to disable copies permits any copies in progress to continue, but prevents initiation of additional copy operations to the specified distributed library. Copy operations continue to queue and operations between other distributed libraries in the TS7700 Grid remain unaffected. A request to enable copies allows the specified distributed library to again become a source for copies and initiate copy operations where it is the target.

Host Override for Cache Residency. You can also use the HCR function to modify how virtual volumes are managed in the tape volume cache. The Host Override for Cache Residency function allows the preference group for a virtual volume to be temporarily overridden while the volume is in cache. This function also permits you to keep a virtual volume in cache longer by making it appear as the most recently accessed volume.

Copy Export Recovery Code Level Limitations. A copy export recovery can occur only within a TS7700 that is operating a code level equal to or later than the microcode level of the TS7700 that exported the physical volumes.